This invention relates to a zeolite device adaptable for the carbonation of aqueous beverages at the point of consumption. Carbonation is accomplished by contacting the water or the beverage to be carbonated with the device comprising "molecular sieves", i.e., crystalline aluminosilicates, which contain adsorbed gaseous carbon dioxide. Carbon dioxide is released from the molecular sieves by displacement with water from the beverage solution. The liberated carbon dioxide is then dissolved into the liquid to form the carbonated beverage. The molecular sieves are bonded into a monolithic structure having sufficient surface area for contact between the aqueous beverage to be carbonated and the molecular sieves so as to provide means for a ready displacement of the carbon dioxide to be released by water from the beverage solution.
Commercial beverage carbonation usually involves carbon dioxide-liquid contact under pressure with intensive mixing in a cooled container. Such commercial methods, of course, require elaborate and sophisticated equipment not available at the point of beverage consumption.
Thus, it was proposed in U.S. Pat. No. 3,888,998, June 10, 1975 to Sampson et al., which was a continuation-in-part of application Ser. No. 200,849, filed Nov. 22, 1971, now abandoned, that aqueous beverages could be advantageously carbonated at the point of consumption with the use of an effective amount of a crystalline aluminosilicate molecular sieve material having adsorbed therein at least about 5% by weight of carbon dioxide.
Molecular sieves of the type used in carbonating beverages at the point of consumption are taught in said U.S. Pat. No. 3,888,998 herein incorporated by reference in its entirety.
Carbonation in accordance with the latter-named method necessitates contacting the molecular sieves with the beverage liquid. Generally, the molecular sieves loaded with CO.sub.2 are placed in a container, and the liquid to be carbonated is then added in sufficient amount to cover the sieves. Heretofore, referred to above, as U.S. Pat. No. 3,888,998, carbonation has been accomplished by utilizing a multiplicity of small molecular sieve agglomerates, such as produced following the teachings of U.S. Pat. No. 2,973,327, issued Feb. 28, 1961, to William J. Mitchell et al., or by utilizing a solid disk of molded and fired molecular sieves. The agglomerates are typically either spherical in shape, commonly known as beads, or roughly cylindrical in shape, commonly known as pellets.
The use of a multiplicity of molecular sieve agglomerates, however, is disadvantageous due to the disadvantages inherent in using the small particles. Since the molecular sieve agglomerates are not in themselves designed for internal consumption, the molecular sieve bodies must be enveloped or otherwise constrained so as to be readily separable from the liquid beverage upon consumption. These various encasements of the molecular sieve bodies may have economical, aesthetic, or other disadvantages which preclude their use for commercial marketing purposes. A composite molecular sieve body would overcome many of these disadvantages inherent in the use of a multiplicity of small agglomerates. However, there are severe technical problems in formulating a suitable monolithic structure. Many of these problems were solved by an extruded zeolite device containing molecular sieves and clay, and having a number of liquid-permeable channels, as taught in U.S. Pat. No. 4,007,134 to Liepa and Japikse, Feb. 8, 1977, herein incorporated by reference in its entirety.
Tabletting problems as stated in the Liepa and Japikse patent are as follows:
"A solid molecular sieve disk, or tablet, made from either compressed molecular sieves or from a mixture of aluminosilicates bonded together with a clay mineral binder tends to be unsatisfactory in that these bodies have encountered problems when used for carbonating liquid beverages. In order to obtain sufficient carbonation of the aqueous beverage, that is, both a sufficient amount of CO.sub.2 released into the beverage and a minimal rate of CO.sub.2 generation to maintain the beverage in a carbonated state, the molecular sieves must have adsorbed therein at least a certain amount of CO.sub.2. However, when these solid disks which contain an effective amount of gaseous carbon dioxide are placed in the liquid beverage environment, the pressure generated by the carbon dioxide release from the molecular sieves is often so extreme as to cause disintegration or destruction of the disk body. If precautions are taken to prevent this, specifically, using a binder composition which imparts sufficient strength to the composite body so as to maintain its structural integrity, then the binder causes a decrease in the rate of release of the carbon dioxide. This can result in either unacceptably low carbonation levels or unacceptably long carbonation times."
Thus, it is the object of the present invention to formulate a fiber reinforced non-fired zeolite rigid composite body which, when charged with a sufficient amount of carbon dioxide, will satisfactorily carbonate an aqueous beverage without the destruction or dissolution of said body.
It is also an object of this invention to provide a non-fired fiber reinforced zeolite tabletted device which effectively carbonates a beverage in a commercially acceptable time period at the point of consumption.
Yet another object of the present invention is to provide a method of making a non-fired rigid composite zeolite tablet.
It is a further object of the instant invention to provide simple but effective devices for suitable gas adsorption. These and other objects readily apparent to those skilled in the art will be apparent from the disclosure and appended claims.